The gravity station data (59,933 records) were compiled by various organizations.
This data base was received in June, 1993. Principal gravity parameters include Free-air
Anomalies and Simple Bouguer Anomalies (no terrain correction applied). The following
assumptions have been made: the observed gravity values are referenced to the International
Gravity Standardization Net 1971 (IGSN 71); the gravity anomaly computation uses the
Geodetic Reference System 1967 (GRS 67) theoretical gravity formula.